Faculty of Science

Permanent URI for this communityhttps://wiredspace.wits.ac.za/handle/10539/20140

For queries regarding content of Faculty of Science please contact Salome Potgieter by email : salome.potgieter@wits.ac.za or Tel : 011 717 1961

Browse

Search Results

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Osteogenic tumour in Australopithecus sediba: Earliest hominin evidence for neoplastic disease
    (Academy of Science of South Africa (ASSAf)., 2016-07) Randolph-Quinney, P.S.; Williams, S.A.; Steyn, M.; Meyer, M.R.; Smilg, J.S.; Churchill, S.E.; Odes, E.J.; Augustine, T.; Tafforeau, P.; Berger, L.R.
    We describe the earliest evidence for neoplastic disease in the hominin lineage. This is reported from the type specimen of the extinct hominin Australopithecus sediba from Malapa, South Africa, dated to 1.98 million years ago. The affected individual was male and developmentally equivalent to a human child of 12 to 13 years of age. A penetrating lytic lesion affected the sixth thoracic vertebra. The lesion was macroscopically evaluated and internally imaged through phase-contrast X-ray synchrotron microtomography. A comprehensive differential diagnosis was undertaken based on gross- and micro-morphology of the lesion, leading to a probable diagnosis of osteoid osteoma. These neoplasms are solitary, benign, osteoid and bone-forming tumours, formed from well-vascularised connective tissue within which there is active production of osteoid and woven bone. Tumours of any kind are rare in archaeological populations, and are all but unknown in the hominin record, highlighting the importance of this discovery. The presence of this disease at Malapa predates the earliest evidence of malignant neoplasia in the hominin fossil record by perhaps 200 000 years.
  • Thumbnail Image
    Item
    The possibility of lichen growth on bones of Homo naledi: Were they exposed to light?
    (Academy of Science of South Africa (ASSAf), 2016-08) Thackeray, J.F.
  • Thumbnail Image
    Item
    Taphonomic analysis of the faunal assemblage associated with the hominins (Australopithecus sediba) from the early pleistocene cave deposits of Malapa, South Africa.
    (Public Library of Science, 2015-06-10) Val, A.; Dirks, P.H.G.M.; Backwell, L.R.; Berger, L.R.; D'Errico, F.
    Here we present the results of a taphonomic study of the faunal assemblage associated with the hominin fossils (Australopithecus sediba) from the Malapa site. Results include estimation of body part representation, mortality profiles, type of fragmentation, identification of breakage patterns, and microscopic analysis of bone surfaces. The diversity of the faunal spectrum, presence of animals with climbing proclivities, abundance of complete and/or articulated specimens, occurrence of antimeric sets of elements, and lack of carnivore-modified bones, indicate that animals accumulated via a natural death trap leading to an area of the cave system with no access to mammalian scavengers. The co-occurrence of well preserved fossils, carnivore coprolites, deciduous teeth of brown hyaena, and some highly fragmented and poorly preserved remains supports the hypothesis of a mixing of sediments coming from distinct chambers, which collected at the bottom of the cave system through the action of periodic water flow. This combination of taphonomic features explains the remarkable state of preservation of the hominin fossils as well as some of the associated faunal material.
  • Thumbnail Image
    Item
    Geological and taphonomic context for the new hominin species Homo naledi from the Dinaledi Chamber, South Africa.
    (eLife Sciences Publications Ltd, 2015-09) Dirks, P.H.G.M.; Berger, L.R.; Roberts, E.M.; Peixotto, B.; Tucker, S.; Kramers, J.D.; Hawks, J.; Randolph-Quinney, P.S.; Elliott, M.; Musiba, C.M.; Churchill, S.; de Ruiter, D.J.; Schmid, P.; Backwell, L.R.; Belyanin, G.A.; Boshoff, P.; Hunter, K.L.; Feuerriegel, E.M.; Gurtov, A.; Harrison, J.G.; Hunter, R.; Kruger, A.; Morris, H.; Makhubela, T.V.
    We describe the physical context of the Dinaledi Chamber within the Rising Star cave, South Africa, which contains the fossils of Homo naledi. Approximately 1550 specimens of hominin remains have been recovered from at least 15 individuals, representing a small portion of the total fossil content. Macro-vertebrate fossils are exclusively H. naledi, and occur within clay-rich sediments derived from in situ weathering, and exogenous clay and silt, which entered the chamber through fractures that prevented passage of coarser-grained material. The chamber was always in the dark zone, and not accessible to non-hominins. Bone taphonomy indicates that hominin individuals reached the chamber complete, with disarticulation occurring during/after deposition. Hominins accumulated over time as older laminated mudstone units and sediment along the cave floor were eroded. Preliminary evidence is consistent with deliberate body disposal in a single location, by a hominin species other than Homo sapiens, at an as-yet unknown date.